[Xen-devel] [PATCH 16/17] PVH xen: elf and iommu related changes to prep for dom0 PVH

[Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>]

This patch prepares for dom0 PVH by making some changes in the elf
code; add a new parameter to indicate PVH dom0 and use different copy
function for PVH. Also, add check in iommu.c to check for iommu
enabled for dom0 PVH.

Changes in V2: None

Changes in V3:
   - introduct early_pvh_copy_or_zero() to replace dbg_rw_mem().

Signed-off-by: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>
---
 xen/arch/x86/domain_build.c       |   39 +++++++++++++++++++++++++++++++++++-
 xen/common/libelf/libelf-loader.c |   40 +++++++++++++++++++++++++++++++++---
 xen/drivers/passthrough/iommu.c   |   22 ++++++++++++++++++-
 xen/include/xen/libelf.h          |    3 +-
 4 files changed, 96 insertions(+), 8 deletions(-)

diff --git a/xen/arch/x86/domain_build.c b/xen/arch/x86/domain_build.c
index c8f435d..f8cae52 100644
--- a/xen/arch/x86/domain_build.c
+++ b/xen/arch/x86/domain_build.c
@@ -307,6 +307,43 @@ static void __init process_dom0_ioports_disable(void)
     }
 }
 
+ /*
+  * Copy or zero function for dom0 only during boot. This because
+  * raw_copy_to_guest -> copy_to_user_hvm -> __hvm_copy needs curr to
+  * point to the hvm/pvh vcpu which is not all setup yet.
+  *
+  * If src is NULL, then len bytes are zeroed.
+  */
+void __init early_pvh_copy_or_zero(unsigned long dest, char *src, int len,
+                                   unsigned long v_start)
+{
+    while ( len > 0 )
+    {
+        char *va;
+        p2m_type_t gfntype;
+        unsigned long mfn, gfn, pagecnt;
+        struct domain *d = get_domain_by_id(0);
+
+        pagecnt = min_t(unsigned long, PAGE_SIZE - (dest & ~PAGE_MASK), len);
+
+        gfn = (dest - v_start) >> PAGE_SHIFT;
+        if ( (mfn = mfn_x(get_gfn_query(d, gfn, &gfntype))) == INVALID_MFN )
+            panic("Unable to get mfn for gfn:%lx\n", gfn);
+        put_gfn(d, gfn);
+
+        va = map_domain_page(mfn) + (dest & (PAGE_SIZE-1));
+        if ( src )
+            memcpy(va, src, pagecnt);
+        else
+            memset(va, 0, pagecnt);
+        unmap_domain_page(va);
+
+        dest += pagecnt;
+        src = src ? src + pagecnt : 0;
+        len -= pagecnt;
+    }
+}
+
 int __init construct_dom0(
     struct domain *d,
     const module_t *image, unsigned long image_headroom,
@@ -766,7 +803,7 @@ int __init construct_dom0(
 
     /* Copy the OS image and free temporary buffer. */
     elf.dest = (void*)vkern_start;
-    rc = elf_load_binary(&elf);
+    rc = elf_load_binary(&elf, (is_pvh_domain(d) ? v_start : 0));
     if ( rc < 0 )
     {
         printk("Failed to load the kernel binary\n");
diff --git a/xen/common/libelf/libelf-loader.c 
b/xen/common/libelf/libelf-loader.c
index 3cf9c59..077f3dd 100644
--- a/xen/common/libelf/libelf-loader.c
+++ b/xen/common/libelf/libelf-loader.c
@@ -108,7 +108,8 @@ void elf_set_log(struct elf_binary *elf, elf_log_callback 
*log_callback,
     elf->verbose = verbose;
 }
 
-static int elf_load_image(void *dst, const void *src, uint64_t filesz, 
uint64_t memsz)
+static int elf_load_image(void *dst, const void *src, uint64_t filesz,
+                          uint64_t memsz, int not_used)
 {
     memcpy(dst, src, filesz);
     memset(dst + filesz, 0, memsz - filesz);
@@ -122,11 +123,25 @@ void elf_set_verbose(struct elf_binary *elf)
     elf->verbose = 1;
 }
 
-static int elf_load_image(void *dst, const void *src, uint64_t filesz, 
uint64_t memsz)
+extern void __init early_pvh_copy_or_zero(unsigned long dest, char *src,
+                                          int len, unsigned long v_start);
+
+static int elf_load_image(void *dst, const void *src, uint64_t filesz,
+                          uint64_t memsz, unsigned long v_start)
 {
     int rc;
     if ( filesz > ULONG_MAX || memsz > ULONG_MAX )
         return -1;
+
+    if ( v_start )
+    {
+        unsigned long addr = (unsigned long)dst;
+        early_pvh_copy_or_zero(addr, (char *)src, filesz, v_start);
+        early_pvh_copy_or_zero(addr + filesz, NULL, memsz - filesz, v_start);
+
+        return 0;
+    }
+
     rc = raw_copy_to_guest(dst, src, filesz);
     if ( rc != 0 )
         return -1;
@@ -260,7 +275,11 @@ void elf_parse_binary(struct elf_binary *elf)
             __FUNCTION__, elf->pstart, elf->pend);
 }
 
-int elf_load_binary(struct elf_binary *elf)
+/*
+ * This function called from the libraries when building guests, and also for
+ * dom0 from construct_dom0().
+ */
+static int _elf_load_binary(struct elf_binary *elf, unsigned long v_start)
 {
     const elf_phdr *phdr;
     uint64_t i, count, paddr, offset, filesz, memsz;
@@ -279,7 +298,8 @@ int elf_load_binary(struct elf_binary *elf)
         dest = elf_get_ptr(elf, paddr);
         elf_msg(elf, "%s: phdr %" PRIu64 " at 0x%p -> 0x%p\n",
                 __func__, i, dest, dest + filesz);
-        if ( elf_load_image(dest, elf->image + offset, filesz, memsz) != 0 )
+        if ( elf_load_image(dest, elf->image + offset, filesz, memsz,
+                            v_start) != 0 )
             return -1;
     }
 
@@ -287,6 +307,18 @@ int elf_load_binary(struct elf_binary *elf)
     return 0;
 }
 
+#ifdef __XEN__
+int elf_load_binary(struct elf_binary *elf, unsigned long v_start)
+{
+    return _elf_load_binary(elf, v_start);
+}
+#else
+int elf_load_binary(struct elf_binary *elf)
+{
+    return _elf_load_binary(elf, 0);
+}
+#endif
+
 void *elf_get_ptr(struct elf_binary *elf, unsigned long addr)
 {
     return elf->dest + addr - elf->pstart;
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 93ad122..64ba44e 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -125,15 +125,25 @@ int iommu_domain_init(struct domain *d)
     return hd->platform_ops->init(d);
 }
 
+static inline void check_dom0_pvh_reqs(struct domain *d)
+{
+    if (!iommu_enabled || iommu_passthrough)
+        panic("For pvh dom0, iommu must be enabled, dom0-passthrough must "
+              "not be enabled \n");
+}
+
 void __init iommu_dom0_init(struct domain *d)
 {
     struct hvm_iommu *hd = domain_hvm_iommu(d);
 
+    if ( is_pvh_domain(d) )
+        check_dom0_pvh_reqs(d);
+
     if ( !iommu_enabled )
         return;
 
     register_keyhandler('o', &iommu_p2m_table);
-    d->need_iommu = !!iommu_dom0_strict;
+    d->need_iommu = is_pvh_domain(d) || !!iommu_dom0_strict;
     if ( need_iommu(d) )
     {
         struct page_info *page;
@@ -146,7 +156,15 @@ void __init iommu_dom0_init(struct domain *d)
                  ((page->u.inuse.type_info & PGT_type_mask)
                   == PGT_writable_page) )
                 mapping |= IOMMUF_writable;
-            hd->platform_ops->map_page(d, mfn, mfn, mapping);
+
+            if ( is_pvh_domain(d) )
+            {
+                unsigned long gfn = mfn_to_gfn(d, _mfn(mfn));
+                hd->platform_ops->map_page(d, gfn, mfn, mapping);
+            }
+            else
+                hd->platform_ops->map_page(d, mfn, mfn, mapping);
+
             if ( !(i++ & 0xfffff) )
                 process_pending_softirqs();
         }
diff --git a/xen/include/xen/libelf.h b/xen/include/xen/libelf.h
index 218bb18..9d695b7 100644
--- a/xen/include/xen/libelf.h
+++ b/xen/include/xen/libelf.h
@@ -192,13 +192,14 @@ int elf_phdr_is_loadable(struct elf_binary *elf, const 
elf_phdr * phdr);
 int elf_init(struct elf_binary *elf, const char *image, size_t size);
 #ifdef __XEN__
 void elf_set_verbose(struct elf_binary *elf);
+int elf_load_binary(struct elf_binary *elf, unsigned long v_start);
 #else
 void elf_set_log(struct elf_binary *elf, elf_log_callback*,
                  void *log_caller_pointer, int verbose);
+int elf_load_binary(struct elf_binary *elf);
 #endif
 
 void elf_parse_binary(struct elf_binary *elf);
-int elf_load_binary(struct elf_binary *elf);
 
 void *elf_get_ptr(struct elf_binary *elf, unsigned long addr);
 uint64_t elf_lookup_addr(struct elf_binary *elf, const char *symbol);
-- 
1.7.2.3


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